Simply tasting beer, with no effect from the alcohol itself, can trigger the release of dopamine in the brain, according to a new study from Indiana University School of Medicine.

For the study, researchers tested 49 men using two scans from positron emission tomography (PET) — one in which they tasted beer, and the second in which they tasted Gatorade.

The investigators were looking for evidence of increased levels of dopamine, a brain neurotransmitter long associated with alcohol and other drugs.

The participants received a very small amount of their preferred beer — about half an ounce — during a 15-minute time period. This allowed the subjects to get a taste of the beer without causing any detectable blood alcohol level or intoxicating effect.

After the participants tasted the beer, the researchers assessed any changes in dopamine levels with a PET scanning compound that targets dopamine receptors in the brain.

The findings revealed significantly more dopamine activity after the participants tasted beer compared to the sports drink. The effect was much greater among those with a family history of alcoholism.

“We believe this is the first experiment in humans to show that the taste of an alcoholic drink alone, without any intoxicating effect from the alcohol, can elicit this dopamine activity in the brain’s reward centers,” said David A. Kareken, Ph.D., professor of neurology at the IU School of Medicine and the deputy director of the Indiana Alcohol Research Center.

Dopamine is a neurotransmitter that is thought to be an important component of the reward centers of the brain. Drugs and alcohol tend to increase dopamine transmission in the brain, but it wasn’t known how little is needed to start the increase.

The more intense effect experienced by participants with close alcoholic relatives suggests that the release of dopamine in response to such alcohol-related cues may be an inherited risk factor for alcoholism, said Dr. Kareken.

For several decades, research has linked dopamine to drug use, although researchers have differing hypotheses of the neurotransmitter’s role. Sensory cues that are closely linked to drug use (ranging from tastes and smells to the sight of a bar) have long been known to ignite cravings and relapse in recovering alcoholics. Many neuroscientists believe that dopamine plays a vital role in these cravings.

In addition to the PET scan findings, participants reported an increased beer craving after tasting beer. They did not experience any cravings following the sports drink — even though many said the Gatorade actually tasted better.

Results of the study are published in the journal Neuropsychopharmacology.